Besides his more famous works of philosophy - Discourse on Method, Meditations on First Philosophy, and Principles of Philosophy - Descartes devoted a great deal of time and thought to the study of physiology and anatomy. An account of his activities in 1629 reports that he visited butcher shops on an almost daily basis to study specific animal organs, and he practiced dissection and even vivisection to explore the workings of major organ systems. In the 1630s, he assisted in the dissection of human cadavers - all to satisfy his intense curiosity about how bodies, animal and human, work. The...